Commit: a50cd989ae (current main)
Environment: Linux x86_64, Node 24.21.0, non-operator Tailscale
Command: node apps/server/src/bin.ts serve --tailscale-serve --tailscale-serve-port 18443 --port 18638 --host 127.0.0.1 --base-dir /tmp/16238-repro-home

[02:27:44.135] WARN (#6747): Failed to configure Tailscale Serve
  {
    cause: {
      _tag: 'TailscaleCommandExitError',
      executable: 'tailscale',
      subcommand: 'serve',
      argumentCount: 4,
      exitCode: 1,
      stderrLength: 197,
      stderrDiagnostic: 'permission-denied'
    },
    localPort: 18638,
    servePort: 18443
  }
T3 Code server is ready.
Connection string: http://127.0.0.1:18638

ss -H -ltnp sport = :18638: LISTEN 127.0.0.1:18638
tailscale serve status --json: {}
Process stayed running until explicitly stopped.
Pairing credentials omitted.